CA (Carrier Aggregation) can be performed in LTE (Long Term Evolution)—Advanced.
The types of CA include “Inter-band CA (CA between different frequency bands)” and “Intra-band CA (CA in the same frequency band”.
A mobile station UE is configured to be capable of setting a reliable “Pcell (Primary cell)” and an additional “Scell (Secondary cell) in a case of performing CA.
Specifically, the mobile station UE is configured to be capable of setting the “Pcell” and then additionally setting the “Scell” if necessary.
For example, in a case of performing CA, the mobile station UE may send an uplink data signal through a PUSCH (Physical Uplink Shared Channel) in a cell #1 and simultaneously send the uplink data signal through the PUSCH also in a cell #2. Alternatively, the mobile station UE may send an uplink control signal through a PUCCH (Physical Uplink Control Channel) in the cell #1 and simultaneously send the uplink data signal through the PUSCH in the cell #2. As another alternative, the mobile station UE may send the uplink data signal through the PUSCH in the cell #1 and simultaneously send a random access preamble through a RACH (Random Access Channel) in the cell #2.
Moreover, in a case of performing “Inter-band CA”, the mobile station UE is configured to be capable of transmitting the uplink signals simultaneously in multiple cells (“Pcell” and “Scell”) operated by carriers of different frequency bands.